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Electrolytic desaturation is a potential method for improving the liquefaction resistance of liquefiable foundations by reducing the soil saturation. In this study, in situ desaturation tests were performed to investigate the resistivity of soil at different depth and water level of the foundation under different currents. The test results show that at constant currents of 1, 2, and 3 A (ampere, unit of the direct current), the saturation of the treated foundation reached 87%, 83%, and 80%, respectively. During the electrolysis process, the generated gas migrates vertically and horizontally under the influence of buoyancy and gas pressure. In the end of electrolysis, the gas inside the sand foundation basically migrates vertically only. The higher current intensity employed for electrolysis will affect the uniformity and stability of the gas. At constant currents of 1, 2, and 3 A, the difference between the maximum and minimum degree of saturation in the treated foundation was 14%, 18%, and 19%, respectively; and after electrolysis had been halted for 144 h, the saturation in the treated foundation was 90%, 85%, and 87%, respectively. The electricity consumption analysis indicates that the desaturation method has excellent economic benefits in the treatment of saturated sand foundations.

Flux pumps have attracted increasing attention due to its capability of energizing superconducting coil wirelessly and avoid thick current leads which cost huge power loss. The transformer-rectifier flux pump is one type of the most important pumps, which is promising in real application. It usually made up of two main parts, the transformer and the dynamic bridge. This paper will investigate the impact of the saturated transformer on working performance of the flux pump. Based on the working principle of the flux pump and the transformer, analysis and comparison on how the saturation degree of the transformer on the flux pump will be carried out. Simulation tests based on Simulink software package will be carried out to verify all the analysis in the paper.

Gas hydrate is regarded as an alternative energy source to fossil fuels in the future. In particular, the pore-filling gas hydrate has the advantages of wide distribution and large reserves, which is of great significance for commercial exploitation. We focus on the amplitude-versus-angle (AVA) patterns of reflection interfaces overlying by different pore-filling minerals deposits in order to identify gas hydrate from marine sediments. The AVA responses of different reflection models are obtained based on rock physics model and approximated Zoeppritz equation. The theoretical results show class III AVA patterns for pore-filling gas hydrate deposits and class IV AVA patterns for other pore-filling minerals deposits. In addition, we analyze the effect of gas saturation and different minerals saturation on the AVA patterns. The prestack seismic data of sites GMGS2-08 and GMGS2-16 in South China Sea is processed and the common reflection point (CRP) gathers are applied to verify our theoretical results. The AVA patterns of actual reflection interface overlying by pore-filling gas hydrate deposits and other pore-filling minerals deposits are class III and IV, respectively, in agreement with theoretical results. And the class IV AVA responses for reflection interfaces overlying by fracture-filling gas hydrate studied by predecessors are also tested in our study area. We then propose a new approach to identify pore-filling gas hydrate from marine sediments by AVA analysis.

The relationship between acoustic emission (AE) and damage source areas in SiC/SiC minicomposites was modeled using insights from tensile testing in-scanning electron microscope (SEM). Damage up to matrix crack saturation was bounded by: (1) AE generated by matrix cracking (lower bound) and (2) AE generated by matrix cracking, and fiber debonding and sliding in crack wakes (upper bound). While fiber debonding and sliding exhibit lower strain energy release rates than matrix cracking and fiber breakage, they contribute significant damage area and likely produce AE. Fiber breaks beyond matrix crack saturation were modeled by two conditions: (i) only fiber breaks generated AE; and (ii) fiber breaks occurred simultaneously with fiber sliding to generate AE. While fiber breaks are considered the dominant late-stage mechanism, our modeling indicates that other mechanisms are active, a finding that is supported by experimental in-SEM observations of matrix cracking in conjunction with fiber failure at rupture.

New universal parameters of the extended corresponding states (ECS) model are presented for hydrofluoroolefin (HFO) refrigerants. The ECS model employing the universal parameters successfully represents the saturation properties. For well-studied HFO refrigerants, which were used to determine the universal parameters, typical deviations between estimations with the ECS model and calculated values with accurate equations of state are within 1 % for vapor pressures and within 3 % for saturated liquid densities at reduced temperatures from 0.6 to 0.9. Similar deviations are expected for other HFO refrigerants if reliable experimental values for the critical parameters and acentric factors are available. If these values are less reliable, larger deviations could be observed, up to 3% and 8 % for vapor pressures and saturated liquid densities, respectively. The ECS model presented here is readily implemented and provides reasonable accuracies; therefore, it is suitable for the preliminary evaluation of novel refrigerants.

This paper aimed to study the effects of fullerene (C60) impregnation on the isoreticular metal-organic framework (IRMOF) materials MOF-650 (ZnO4 nodes were connected to azulenedicarboxylate linkers), MOF-5(ZnO4 nodes were connected to benzenedicarboxylate linkers), and IRMOF-10 (ZnO4 nodes were connected to biphenyldicarboxylate linkers) for H2 storage, these IRMOFs had similar structures but different pore volumes and organic linkers. Density functional theory (DFT) and grand canonical monte Carlo (GCMC) calculations indicated that C60 plays an important role in balancing the gravimetric and volumetric H2 densities of the IRMOFs. The C60@IRMOFs revealed improved volumetric density when H2 was undersaturated but reduced gravimetric density under H2 saturation. The saturated gravimetric H2 density of the IRMOFs was decided by the free volume. At 77 K, C60@MOF-650 had a gravimetric H2 density of 5.3 wt% and volumetric H2 density of 42 g/L under 10 bar, and C60@IRMOF-10 had a gravimetric H2 density of 7.4 wt% and volumetric H2 density of 43 g/L under 18 bar. These values nearly meet the United States Department of Energy (DOE) gravimetric and volumetric H2 density ultimate targets (gravimetric H2 density, 6.5 wt%; volumetric H2 density, 50 g/L) under ambient pressures. Among the studied IRMOFs, C60@MOF-650 and C60@IRMOF-10 demonstrated the best H2 storage properties at 233 and 298 K.

In this paper we present the application of a single-loop litho-petro-elastic (LPE) inversion, which is a data assimilation algorithm that uses nonlinear Zoeppritz reflectivity operators with sequential filtering. It integrates rock physics models with seismic amplitude variation with offset (AVO) inversion and Bayesian inversion to define lithology, elastic, and petrophysical properties in a single loop, thus, combining several steps of the conventional reservoir characterization workflow. In the conventional multistep approach, the lithology and petrophysical properties are generated sequentially from elastic properties after AVO inversion is performed, which can add prediction uncertainty at each step and produce results that are not correlated with each other. The LPE inversion ensures that the predicted properties maintain the relationships defined by the rock physics model. The LPE inversion was tested on data from offshore Australia with three wells, for a faulted reservoir zone containing oil with a gas cap. It provided robust predictions for lithology, porosity, and water saturation, which matched acceptably at the three wells. The algorithm also accounted for subsurface uncertainties as it produced prediction probabilities of facies, porosity, and water saturation using multidimensional probability density functions. This approach can be effectively used to classify reservoir properties in a single-loop workflow.

The concentration of sulfur that can be dissolved in a silicate liquid is of fundamental importance because it is closely associated with several major Earth-related processes. Considerable effort has been made to understand the interplay between the effects of silicate melt composition and its capacity to retain sulfur, but the dependence on pressure and temperature is mostly based on experiments performed at pressures and temperatures below 6 GPa and 2073 K. Here we present a study of the effects of pressure and temperature on sulfur content at sulfide saturation of a peridotitic liquid. We performed 14 multi-anvil experiments using a peridotitic starting composition, and we produced 25 new measurements at conditions ranging from 7 to 23 GPa and 2173 to 2623 K. We analyzed the recovered samples using both electron microprobe and laser ablation ICP-MS. We compiled our data together with previously published data that were obtained at lower P-T conditions and with various silicate melt compositions. We present a new model based on this combined data set that encompasses the entire range of upper mantle pressure-temperature conditions, along with the effect of a wide range of silicate melt compositions. Our findings are consistent with earlier work based on extrapolation from lower-pressure and lower-temperature experiments and show a decrease of sulfur content at sulfide saturation (SCSS) with increasing pressure and an increase of SCSS with increasing temperature. We have extrapolated our results to pressure-temperature conditions of the Earth’s primitive magma ocean, and show that FeS will exsolve from the molten silicate and can effectively be extracted to the core by a process that has been termed the “Hadean Matte.” We also discuss briefly the implications of our results for the lunar magma ocean.

In this paper, a systematic study of the relationship between nonlinear crystal length and intracavity second-harmonic generation (SHG) using MgO-doped periodically-poled lithium niobate (MgO:PPLN) is presented. The experimental results demonstrate a relationship between the maximum SHG power generated and the full-width at half maximum (FWHM) of the crystal’s temperature tuning curve to the length of the nonlinear optical crystal. It was shown that maximum SHG power increases rapidly with the increase of MgO:PPLN length, reaching a saturation length (~2 mm), which is much shorter than that predicted by the single-pass SHG theory. This saturation length of the MgO:PPLN crystal is almost independent on 808 nm pump power for typical powers used in continuous wave intracavity SHG lasers. In addition to this saturation effect, a broadening effect was also observed, the FWHM of the temperature tuning curve was shown to have a larger FWHM than that predicted by the single-pass SHG theory for MgO:PPLN shorter than the saturation length. This work has the benefit of allowing engineers to optimize nonlinear crystal length when developing intracavity SHG based diode-pumped solid state (DPSS) lasers.

In the last few years, there has been a lot of interest in making smart components, e.g. robots, able to simulate human capacity of object recognition and categorization. In this paper, we propose a new revolutionary approach for object categorization based on combining the HOG (Histograms of Oriented Gradients) descriptors with our two new descriptors, HOH (Histograms of Oriented Hue) and HOS (Histograms of Oriented Saturation), designed it in the HSL (Hue, Saturation and Luminance) color space and inspired by this famous HOG descriptor. By using the chrominance components, we have succeeded in making the proposed descriptor invariant to all lighting conditions changes. Moreover, the use of this oriented gradient makes our descriptor invariant to geometric condition changes including geometric and photometric transformation. Finally, the combination of color and gradient information increase the recognition rate of this descriptor and give it an exceptional performance compared to existing methods in the recognition of colored handmade objects with uniform background (98.92% for Columbia Object Image Library and 99.16% for the Amsterdam Library of Object Images). For the classification task, we propose the use of two strong and very used classifiers, SVM (Support Vector Machine) and KNN (k-nearest neighbors) classifiers.

Availability of gases at the field level makes attractive to water-alternating-gas (WAG) process for low viscosity and light oils carbonate reservoir. However, impact of reservoir heterogeneity on WAG performance is crucial before field application. In general, ramp carbonates have heterogeneity due to variation of permeability and porosity. However, WAG performance significantly affected by permeability variations. This article investigates merits and demerits of WAG displacement due to permeability heterogeneities such as permeability anisotropy, high permeability streaks (HKS), matrix permeability, dolomite and thin dense stylolite layers. High-resolution compositional simulations with tuned equation of state (EoS) were carried out using 2D and 3D sector models. The study focuses on WAG performance in terms of oil recovery, vertical sweep, solvent utilization, gas oil ratio (GOR), water cut (WCT), WAG response time, gravity override, hysteresis, un-contacted oil saturation and economics. The results of simulation show that the heterogeneous reservoir provides initially faster WAG response, lower expected ultimate recovery (EUR), faster gas breakthrough, higher GOR and WCT production compared to homogeneous reservoir. The gas gravity override at smaller wells spacing is less in homogeneous reservoir as compared to heterogeneous reservoir, but it is reverse in case of larger well spacing. In heterogeneous reservoir, the HKS shows significant gas override resulting in poor vertical sweep due to capillary holding, and the high permeability dolomite layer shows early water breakthrough. This reservoir has higher solvent utilization in initial stage, and then, it becomes nearly equal to homogeneous reservoir. Simulation in both reservoirs overestimates incremental recovery of 2–3% OOIP at one pore volume injection because of not involving un-contacted oil saturation as predicted in core flood. The findings of this study will help to understand WAG performance and design in highly heterogeneous reservoirs for field applications. Graphical abstract

SWCTT (Single-Well Chemical Tracer Test) actively used to determine the reservoir oil saturation as cost effective and quick method. To use this technology, the partition coefficients K and hydroly...

Molecular hydrogen is one of the effective antioxidants, which not only does not disrupt normal metabolism in the body, but also activates its antioxidant systems. Hydrogen-saturated water has antioxidant, anti-inflammatory, anti-allergic, anti-apoptotic properties, stimulates energy metabolism and contributes to the systemic recovery of the body. It is used as a therapeutic factor for the treatment of patients with various pathologies: arterial hypertension, coronary heart disease, diabetes, obesity, metabolic disorders, disorders of the musculoskeletal system. The article discusses the various methods of obtaining molecular hydrogen and hydrogen water (direct and indirect saturation). Technical characteristics are described and features of the hydrogen generator GVCh Life (manufacturer LTD «Chemtest Ukraine+», Kharkiv, Ukraine), which produces molecular hydrogen (purity of which is 99.99 %, productivity — 100 ml/min) and saturates water with it (https://chemtest.com.ua/generator_vodorodnoy_vodi_i_dihanie_gvch_life). In contrast to the problems of most known generators in the device GVChLife is completely no contact of the electrodes with water, so it is not subject to electrolysis and is not saturated with metal ions. Water saturated in this way has the following characteristics: redox potential 560 mV, hydrogen concentration 1.0–1.15 ppm(water volume 1 l, saturation duration 10 min). The generator can be used for both hydrogen saturation and hydrogen inhalation. In the case of therapeutic use of hydrogen water to obtain it, you can use any drinking water (spring, prepared or non-carbonated bottled), hydrogen inhalation using nasal cannulas. Inhalation of pure hydrogen gas (99.99 %) for 30 minutes is equal to the use of 15 liters of hydrogen water (concentration 1.1–1.2 ppm). Conclusions. The developed MoHC Life molecular hydrogen generator is safe to use, without special requirements during operation. It can be successfully used in the complex therapy of patients with various diseases, including musculoskeletal system., Молекулярний водень є одним з ефективних антиоксидантів, який не лише не порушує нормальний метаболізм в організмі, а ще й активізує його антиоксидантні системи. Вода, насичена воднем, має антиоксидантні, протизапальні, протиалергічні, антиапоптозні властивості, стимулює енергетичний метаболізм та сприяє системному оздоровленню людини. Її використовують як лікувальний чинник для терапії пацієнтів із різною патологією: артеріальною гіпертонією, ішемічною хворобою серця, цукровим діабетом, ожирінням, порушенням обміну речовин, порушеннямиопорно-рухової системи. У статті обговорено різні способи одержання молекулярного водню та водневої води (пряма та непряма сатурація). Описано технічні характеристики та особливості генератора водню ГВЧ Life (виробник ТОВ «Хімтест Україна+», м. Харків, Україна), який виробляє молекулярний водень (чистота якого дорівнює 99,99 %, продуктивність — 100 мл/хв) і насичує ним воду (https://chemtest.com.ua/generator_vodorodnoy_vodi_i_dihanie_gvch_life). На відміну від більшості відомих генераторів у приладі ГВЧ Life повністю відсутній контакт електродів із водою, завдяки чому вона не піддається електролізу та не насичується іонами металів. Водень потрапляє до води через розпилювач. Насичена в такий спосіб вода має такі характеристики: окислювально-відновний потенціал 560 mV, концентрація водню 1,0–1,15 ppm (об’єм води 1 л, тривалість насичення 10 хв). Генератор можна використовувати і для насичення воднем води, і для інгаляцій воднем. У разі терапевтичного вживання водневої води для її отримання можна застосовувати будь-яку питну воду (джерельну, підготовлену абонегазовану бутильовану), інгаляції воднем. Вдихання чистого газоподібного водню (99,99 %) протягом 30 хв дорівнює вживанню 15 л водневої води (концентрацієя 1,1–1,2 ppm). Висновки. Розроблений генератор молекулярного водню ГВЧ Life є безпечним у користуванні, без особливих вимог під час експлуатації. Він може з успіхом бути застосованим у комплексній терапії пацієнтів із різними захворюваннями, у тому числі опорно-рухової системи.

Permeable asphalt mixtures are widely used to achieve good permeability of the pavements used for urban road surfaces. Based on the law of water migration in permeable road structures, the water-holding performance of permeable asphalt mixtures was analyzed and the evaluation indexes were determined. Open-graded asphalt friction course (OGFC-13) permeable asphalt mixture was selected, and the changes in the saturation, water retention, and water-holding rate of OGFC-13 permeable asphalt mixtures with different porosities were compared using water-holding equipment. The water-holding characteristics of permeable pavement materials under different seepage conditions were analyzed. A model of the relationship governing the water-holding capacity of the permeable asphalt mixture, water action conditions, and material porosity was established by a linear fitting method, and the reliability of the model was verified by comparison with laboratory test results, providing a foundation for related research on the water-holding and cooling behavior of permeable pavements.

Wood has been utilized as a heat conductor or insulator. Hence, this research aims to discover the thermal conductivity of teak wood using thinned stands from the Perhutani plantation forest. The samples obtained had varying moisture content and fiber direction, and were of distinct tree ages, at 12, 15, 20, 25, and 60 years. This result show that the thermal conductivity in air-dry conditions and fiber saturation points were 0.116 to 0.128 and 0.338 to 0.151 in W/Mk, respectively. The analysis of variance showed that the thermal conductivity of teak wood was affected by the interaction of fiber directions and moisture content but not significantly by tree age. Also, there was a weak relationship found between thermal conductivity and specific gravity in air-dry conditions and longitudinal direction.

The classification is carried out and the characteristics, capabilities and disadvantages of the known methods of programmed correction of the output current of a single-phase primary measuring channel (PMC) of the current are determined. A discretized model of short-circuit current (SCC) is proposed. A method and an algorithm for increasing the accuracy of a three-phase current PMC in transient modes of electric power systems (EPS) under the condition of saturation of the magnetic circuits of its phase current transformers have been developed. The reliability of the developed method is confirmed by simulation of the PMC output current under the condition of phase-to-phase short-circuit of phases A and B without correction and with correction of its phase currents. It is shown that the developed method makes it possible to reduce the total error of the PMC in the transient modes of the EES under the condition of saturation of the magnetic circuits of the CT from 70-90% to 6-15%. References 47, figures 6, table 1.

A bentonite buffer is an important component of the engineering barrier of a high-level radioactive waste (HLW) repository, which can delay the infiltration of groundwater and retard the migration of radionuclides. The long-term-coupled thermo-hydro-mechanical (THM) performances and the retardation capacities of composite bentonite buffers are studied in this work. A theoretical coupled THM model is presented, and a finite element code, namely LAGAMINE, is used for the numerical simulation under coupled THM conditions. Six kinds of composite bentonite buffer computational models are considered. The boundary conditions of these models and computational parameters of bentonite are presented. The repository time for HLW is considered to be 10,000 years. The evolution processes of temperature, saturation degree and swelling pressure are presented according to the computational results. The combination forms of blocks and joints have an obvious influence on the swelling pressure in the bentonite buffers. The circumferential and radial joints can significantly reduce the maximum value of the swelling pressure. The influence coefficient for the retardation capacity ψ is proposed for evaluating the retardation capacity of composite bentonite buffers. According to the value of ψ, the six kinds of computational models are ranked in terms of retardation capacity, and three kinds of models are suggested for usage in design. The results of this investigation are helpful for optimising the design of bentonite buffers for HLW repositories.

Soil behaviour may be hinged on the relative composition and nature of arrangement of the various component fractions embedded in the soil. Whether the component proportions of the fines (silt/clay) are interwoven within the voids of coarse (sand) grains, or that the coarse grains are dispersed within the fines mass would determine sandy or clayey soils characteristics. Density and voids ratio assessments of tropical residual soils were conducted in this study on compacted reconstituted binary blends of fines and coarse soils which were also subjected to cycles of sustained compression loads. The soil was separated into fines and coarse fractions by sieving through a 75μm sieve. Reconstituted soil samples were prepared from these two fractions in varying percentages ranging from zero fines content (0:100) to 100 percent fines fraction (100:0) in 10 percent increment. The results indicate that the moisture contents and changes in density due to moisture movements were insignificant for fines less than 40 percent. Compacted density and voids ratios were optimally maximum and minimum with values of about 2000kg/m3(dry density) and 0.2 respectively at fines contents of 20 percent. An optimal degree of saturation was also obtained at 20 percent fines. Optimum moisture contents were also obtained at about 30 percent with the corresponding optimum dry densities ranging from 2100kg/m3 to 2200kg/m3 from compression tests. The thresholds fines content therefore would depend on the stress state of the soil and may be about 20 or 30 percent for subgrade assessments or geotechnical considerations respectively and beyond the threshold fines content the fines fraction makes up the stress-carrying matrix for the soil mass thus controlling the soil behaviour.

We focus on studying the dynamics of bulk semiconductor optical amplifiers and their effects on the saturation region for short pulse that differ, however there is the same unsaturated gain for both dynamics. Parameters like current injection, fast dynamics present by carrier heating (CH), and spectra hole burning (SHB) are studied for regions that occur a response to certain dynamics. The behavior of the saturation region is found to be responsible for phenomena such as recovery time and chirp for the pulse under study.

Input saturation is very important for the analysis and design of control system. Ignoring the input saturation will have an adverse effect on the control system, and even cause the control system ...

This study involves understanding the effect of tricycles on saturation flow rate at signalized intersections. The goal is to show that intersection dominated by tricycle experience congestion especially at peak periods (morning and evening). This was done by collecting vehicular traffic data, signal timing and geometric data from five (5) signalized intersections at ten (10) cycles. The period covered October, 2015 to June, 2016 for four working days of the week (Mondays, Tuesdays, Wednesdays, and Fridays), between the hours of 7:30 am–9:30 am and 4:30 pm– 6:30 pm. The duration of data collected covered both rainy and dry seasons. Average vehicular departure time during green time was determined and saturation flow obtained through field measurement by the ratio of average vehicular departure time to green time. Highway Capacity Manual method was also used to obtain saturation flow at each study approach. Saturation flow obtained through field measurement and Highway Capacity Manual were compared using independent t-test having t-value of 4.239 and P-value of 0.000 at 20 degree of freedom were obtained. The analysis indicated that P-value is less than 0.05, hence the mean of Highway Capacity Manual 2000 Model (5918.60) was significantly higher than the field measurement (4687.50). The result indicated that the increasing rate of tricycle with non-lane discipline causes congestion at signalized intersection. The findings suggest that the widely used Highway Capacity Manual is not appropriate for determining saturation flow for a mixed traffic with increasing rate of tricycle coupled with non-lane discipline traffic condition. From the analysis, it is recommended that Government should give priority to use of buses as a means of mass transit system so that it can accommodate more commuters than tricycle.

Excess inputs of reactive nitrogen (Nr) from the atmosphere will cause disturbances to forest ecosystems, including soil and stream water acidification, plant nutrient imbalances, alterations of sp...

Industrial wastewater may have a long-time effect on the environment and human life as it goes underground and causes serious pollution continuously. To have a well understanding of the migration of such wastewater is a basic task for industrial wastewater treatment as well as industrial design. To study the migration mechanism of industrial wastewater in rock formations, the governing equations such as mechanics, seepage, heat, and mass transfer are reviewed, referenced, and proposed. The thermal (T)-hydraulic (H)-mechanical (M) coupled model of the multimedia of matrix-fault and matrix-fracture-fault is established. The influence of the fault and the fractures on the pressure distribution and contaminant migration is analyzed. The influence of fault length, width, dip angle, permeability, and temperature of wastewater on contaminant migration is parametrically studied. The following results can be obtained. (1) The fracture quantitively affects the concentration distribution, while the fault dominates the concentration distribution and contaminant migration. (2) The migration of the contaminants can be geometrically divided into 3 zones along the direction of the fault: the saturation zone, the rapid diffusion zone, and the concentration decrease zone. (3) There is a peak of the concentration along the bottom of the model. The position of the peak is the projection of the endpoint of the fault. (4) The fault length has the most significant effect on contaminant accumulation. The temperature of the wastewater has the minimum effect on the contaminant accumulation. (5) The accumulation of concentrations can be divided into 2 stages, the slow growth stage (before 20 years) and the rapid growth stage (after 20 years). The main channel of contaminant migration in the slow growth stage is a fault. During the rapid growth stage, the contaminants penetrate through the rock matrix as well as the fault.

The density, ρ, of a limited mixing LiF + AgI and LiBr + AgI melts was measured in the temperature range from the melting point to the critical mixing temperature by means of the hydrostatic weight procedure. It is shown that the density of LiBr + AgI melt along the saturation line is due to both by the intensity of the thermal movement of ions and the composition of the phases. The difference between the densities for the equilibrium phases ∆ρ is found to decrease when the temperature elevated tending to zero at Tc = 984 K. The critical index for the density of the melt studied (0.45) is shown to be 10% less than that found for the mixtures of alkali halides. The melt containing LiF exists in two phases up to temperature of 1223 K. The covalent bonding between the silver and halide ions can be understood as causing the difference between the critical exponents of the alkali halide melts and those of silver iodide-containing mixtures.

Marine natural gas hydrate has recently attracted global attention as a potential new clean energy source. Laboratory measurements of various physical properties of gas hydrate-bearing marine sediments can provide valuable information for developing efficient and safe extraction technology of natural gas hydrates. This study presents comprehensive measurement results and analysis of drilled hydrate-bearing sediments samples recovered from Qiongdongnan Basin in the South China Sea. The results show that the gas hydrate in the core samples is mainly methane hydrate with a methane content of approximately 95%, and the other components are ethane and carbon dioxide. The saturation of the samples fluctuates from 2%–60%, the porosity is approximately 38%–43%, and the water content is approximately 30%–50%, which indicate that high water saturation means that timely drainage should be paid attention to during hydrate extraction. In addition, the median diameter of the sediment samples is mainly distributed in the range of 15 to 34 µm, and attention should be paid to the prevention and control of sand production in the mining process. Moreover, the thermal conductivity is distributed in the range of 0.75 to 0.96 W/(m·K) as measured by the flat plate heat source method. The relatively low thermal conductivity of hydrates at this study site indicates that a combined approach is encouraged for natural gas production technologies. It is also found that clay flakes and fine particles are attached to the surface of large particles in large numbers. Such characteristics will lead to insufficient permeability during the production process.

Isothermal mutual diffusion coefficients (interdiffusion coefficients) were measured for K2SO4(aq) at 298.15 ± 0.005 K, at numerous concentrations ranging from dilute solutions to near saturation (0.59648 mol·dm–3; 0.61349 mol·kg–1) under free diffusion boundary conditions, using high precision Rayleigh interferometry. Under the experimental conditions these diffusion coefficients are on the volume-fixed reference frame Dv. Two series of experiments were performed, the first using the traditional experimental approach with a mercury lamp source and with the interference patterns being recorded on glass photographic plates, and the second with a He–Ne laser light source and computerized data acquisition using a photodiode array. The results from both series of experiments are in excellent agreement, and generally yield diffusion coefficients precise to at least 0.002 × 10–9 m2·s–1 (0.15% to 0.19%) and in most cases to 0.001 × 10–9 m2·s–1 (0.07% to 0.1%). These experiments also yield accurate values of the refractive index differences for the solution pairs used in the diffusion experiments. The new diffusion coefficients are compared to two sets of published values of diffusion coefficients for K2SO4(aq) which are somewhat discrepant from each other. This study extends and complements our earlier work on the diffusion coefficients of the most common brine salts: NaCl(aq), KCl(aq), MgCl2(aq), CaCl2(aq), Na2SO4(aq),]MgSO4(aq), NaHCO3(aq), and KHCO3(aq) at 298.15 K.

In cold regions, a better understanding of soil thermal conductivity is necessary for a variety of earthworks and engineering applications such as ground heat exchanger piles and energy piles, installation of underground power cables, and so on. In this study, the effects of the internal factors of the soil such as water content, dry density, porosity, saturation degree, and the external factors of the soil like freeze–thaw cycles and temperatures were studied on the thermal conductivity (λ) of the sandy soil. The λ values of the soil samples were determined at six different volumetric water contents (0.190, 0.212, 0.230, 0.246, 0.260, and 0.320 m3 m−3) and four frozen temperatures (4 °C, − 7 °C, − 12 °C and − 20 °C) under five different numbers of freeze–thaw cycles (0, 2, 5, 9, and 12). Then, new prediction models based on the internal (the ANN-I model) and both internal and external factors (the ANN-G model) of the soil proposed by artificial neural network (ANN) technology. The developed ANN models were compared with three empirical models (Tortuosity-Parallel model, Farouki model, and de Vries model) to verify their reliability and effectiveness. The results showed that dry density, water content, porosity, saturation degree, and temperature have significant and variable influences on the λ of the soil subjected to repeated freeze–thaw cycles. The ANN-G model provided the highest accuracy in predicting the λ with increasing numbers of freeze–thaw cycles. For frozen sandy soil samples subjected to repeated freeze–thaw cycles, the Tortuosity-Parallel model exhibited the best performance, followed by the Farouki model and the de Vries model with the poorest performance.

This article investigates the course tracking of ships subject to parametric uncertainties and environmental disturbances. Particularly, the actuator dynamics with input magnitude and rate saturation is also considered. When including the actuator dynamics, the ship course tracking system becomes a mismatching system, which brings a great difficulty to the control design. A novel robust command filtered control strategy is presented by incorporating a disturbance observer and an auxiliary anti-saturation system into the command filtered backstepping control architecture. The disturbance observer is designed to compensate for the mismatched lumped disturbance. The auxiliary anti-saturation system is introduced to tackle the effects of input magnitude and rate saturation. It is strictly proved that all the closed-loop error signals under the proposed controller are uniformly ultimately bounded and the course angle tracking error can converge to the adjustable small region around the origin. Moreover, the proposed controller is computationally simple and has the strong robustness against uncertainties and disturbances. The effectiveness and advantages of the proposed control strategy are verified through simulations and comparisons.

Organic field-effect transistors (OFETs) are becoming popular because of the ease associated with their fabrication and cost-effectiveness. Numerous models have been developed to predict the room temperature $$I-V$$ characteristics of OFETs involving their design, as well as material parameters. In this paper, we discuss efforts that have been made to develop a compact model which can be employed by design engineers with reasonable ease without compromising the accuracy of modeled characteristics. Both for linear and for saturation region of $$I-V$$ characteristics, a single expression involving a hyperbolic tangent function has been proposed. The proposed model addresses typically observed contact resistances of drain–source electrodes by incorporating the effective drain-to-source potential and thus generates OFETs output characteristics with improved accuracy. A modification in the device threshold voltage is proposed to improve modeled data of short channel OFETs. It has been demonstrated by evaluating root mean squared error (RMSE) values that the proposed technique is at least $$15\%$$ better than the best reported model of OFETs.

This study is dealt with the two-phase binding (specific and nonspecific) of drug eluted from a half- embedded drug-eluting stent in presence of atherosclerotic plaque. The specific binding due to the interaction of drug molecules with specific receptors and nonspecific binding caused by the trapping of drug in the extra-cellular matrix have been paid due attention. An idealised wall consisting of a plaque and a healthy tissue region has been considered. Moreover, a Dirichlet release condition is imposed on the strut surface. In this investigation, a two-dimensional model governing drug transport and its two-phase binding in cylindrical polar coordinate system has been solved numerically by a finite-difference method. Our simulation predicts that plaque behaves like a physical barrier in two types of the binding process and there is an inverse relationship between bound drug concentration and plaque thickness. Simulations show that a single peak profile of drug is noted when the struts are situated one-strut radius apart and as the inter-strut distance increases, the peak concentration falls and distinct peak profiles over each strut are visualised. The model also reveals that in the region downstream of a strut, the concentration of both bound drug forms in the plaque and healthy regions increases, and eventually, the saturation length of binding sites increases. Predicted results show for smaller Damköhler number, the rapid saturation of binding sites takes place and the stent having thinner strut may perform well in terms of effectiveness as well as efficacy in the stent-based delivery.

Used to reduce damage from rainfall-induced landslides and establish disaster-warning systems, physically based stability models are efficient tools for evaluating spatial or temporal patterns of susceptibility to shallow landslides. Such comprehensive models can be classified as dynamic and steady hydrological models, which combine the simulation of dynamic or steady-state subsurface saturation generation with slope stability analysis. Although numerous dynamic and steady models have been proposed and validated against actual landslides, comprehensive comparisons of the performance and detection preferences for topographic characteristics (hereafter, topographic preferences) between the dynamic and steady models are lacking. Based on detailed observational data on topography at the soil–bedrock interface, this study compared numerical predictions from dynamic and steady models to a case of rainfall-induced shallow landslides in a small catchment. The dynamic model was based on time-varying generation of subsurface saturation using the three-dimensional Richards equation, and the steady model was based on the steady-state distribution of subsurface saturation. The results showed that both the dynamic and steady models could generally detect cells at risk of failure in the landslide areas. However, the precision of the dynamic model was approximately double that of the steady model. Rainfall patterns had significant impacts on the timing and locations of landslides, and the delayed rainfall peak pattern was most prone to landslides, which was reflected by the dynamic model but not the steady model. The steady model underestimated instability or the number of unstable locations relative to the dynamic model. This study revealed that the topographic preference at the soil–bedrock interface differs between the models. The dynamic model exhibited topographic preference in detecting landslides with deep soil depth and steep gradient, whereas the steady model was better for detecting landslides with large contribution areas. The elucidation of such topographic preferences for landslide types is crucial for comparing the performance of dynamic and steady models.

In this article, the problem of decentralized full-state constrained adaptive tracking control is investigated for interconnected time delay systems with input saturation. The extreme learning machine is applied to approximate the unknown nonlinear function in the design process. By selecting the appropriate Lyapunov–Krasovskii function, the time delay interconnection term could be compensated. A unified barrier function is introduced to ensure that the constraints imposed on all states are not violated. The Nussbaum function is introduced to deal with the problem of input saturation. By applying adaptive backstepping procedures, a novel decentralized full-state constrained adaptive tracking control strategy is proposed for the considered interconnected time delay systems. In terms of Lyapunov stability theory, it is proved that all the signals of the closed-loop systems are semi-global ultimately uniformly bounded and all state variables could be constrained within the time varying asymmetric boundaries. Finally, the effectiveness of the proposed scheme is illustrated by a simulation example of a two-stage chemical reactor.

In this study, the problem of optimal guaranteed cost control (OGCC) for nonlinear systems under input saturation is investigated. The purpose is to design a dynamic output feedback controller such that the closed-loop system is asymptotically stable and the upper bound of the cost function is minimized. Moreover, the designed controller ensures that the control signals do not exceed their permissible values. This leads to an optimization problem with bilinear matrix inequality (BMI) constraints. The BMI conditions are converted into the linear matrix inequality conditions by using some technical lemmas for straightforward computation of the controller matrices. The simulation results show the effectiveness and advantages of the proposed theoretical results.

PURPOSE: HyperCEST contrast relies on the reduction of the solvent signal after selective saturation of the solute magnetization. The scope of this work is to outline the experimental conditions needed to obtain a reliable hyperCEST contrast in vivo, where the “solvent” signal (i.e., the dissolved-phase signal) may change over time due to the increase in xenon accumulation into tissue. METHODS: Hyperpolarized (129)Xe was delivered to mice at a constant volume and rate using a mechanical ventilator, which triggered the saturation, excitation, and acquisition of the MR signal during the exhale phase of the breath cycle, either every breath or every two, three, or four breaths. Serial Z-spectra and hyperCEST images were acquired before and after a bolus injection of cucurbit[6]uril to assess possible signal fluctuations and instabilities. RESULTS: The intensity of the dissolved-phase xenon signal was observed to increase immediately after the beginning of the hyperpolarized gas inhalation and NMR acquisition, and then decrease before reaching a steady state condition. Once a steady state dissolved-phase magnetization was established, a reliable hyperCEST contrast, exceeding 40% signal reduction, was observed. CONCLUSION: A reliable hyperCEST contrast can only be obtained after establishing a steady-state dissolved phase (129)Xe magnetization. Under stable physiological conditions, a steady-state dissolved-phase xenon magnetization is only achieved after a series of xenon inhalations and RF excitations, and it requires synchronization of the breathing rate with the MR acquisition.

With increasing CO2 concentration in the atmosphere, CO2 geo-aequestration has become a popular technique to counter the dangers of global warming resulting from high levels of CO2 in the atmosphere. This paper examins sequestration parameters such as CO2 plume behaviour, residual gas trapping and injectivity as a means of achieving safe and successful CO2 storage in saline aquifers. Mineral precipitation/dissolution rates are used to establish a relationship between these parameters and geochemical reactions in saline aquifers. To achieve this, mechanistic models (6 models with different inputs, created using CMG – GEM, 2016 and WINPROP, 2016) are simulated using input data from literature and studying changes in fluids and formation properties as well as mineral precipitation/dissolution rates in aquifers when subjected to different conditions in the different models. The results from the models show that high CO2 dissolution, which creates large CO2 plume, leads to high mineral dissolution/precipitation as results of increased fluid-rock interactions (geochemical reactions); whereas injectivity, although enhanced by CO2-water cyclic injection, does not show much increase in bottom hole pressure when mineral trapping (thus geochemical reactions) is introduced into the model. Sensitivity study on residual gas trapping shows that high residual gas saturation leads to reduced mineral precipitation/dissolution due to the reduced amount of dissolved CO2 in brine. Also, rapid changes in the bottom hole pressure at high residual gas saturation means that a formation that fosters high residual gas trapping, rather than CO2 dissolution in brine, is more likely to experience injectivity issues during the sequestration process.

Plastic soil exhibits unfavorited geotechnical properties (when saturation), which causes negative defects to engineering structures. Different attempts (included various materials) were conducted to proffer solutions to such defects by experimenting in practical ways. On one hand, these attempts aimed to improve the engineering characteristics of plastic soil, and on the other hand, to use problematic waste materials as a stabilizer, like cement kiln dust, and to reduce environmental hazards. This paper explored the shrinkage, plasticity, and strength behavior of plastic soil enhanced with cement dust. The cement dust contents were 0%, 5%, 10%, 15% and 20% by dry weight of soil. An experimental series of shrinkage and plasticity tests and unconfined compression tests were carried out to explore the effects of cement dust on the quantitative amount of shrinkage, plasticity characteristics, and shear strength experienced by plastic soil. The effects of curing on soil strength were also investigated. The finding of this paper showed that the critical behavior and plasticity of plastic soil could be reduced by mixing the soil with 15% or 20% of cement dust. The undrained shear strength, cu, of plastic soil-cement dust mixtures increased with the increasing dust content up to 20%. In fact, this strength was affected by the curing period. The best enhancement was attained when the content of cement dust was 20%, and the undrained shear strength was increased more than three times at this content.

In chemo-mechanical coupling of clays, chemical phenomena are likely to have a stronger influence on the mechanical behaviour and mechanical actions can modify the chemical behaviour. The understanding of these different phenomena, taking into account the coupled mechanisms, is essential in the context of the problem of the durability of structures and works built on polluted sites. Thus, the laboratory characterisation of the chemo-mechanical behaviour of a clay contaminated by light hydrocarbon pollutant (BTEX: benzene) was carried out. First in the absence of pollutants, i.e., by the presence of water only, then under the influence of the pollutant, all in two stages: with no external stress, then under imposed external stress. This study presents an experimental protocol based on a series of uniaxial consolidation tests, specific oedometric tests and direct shear strength, this tests performed under controlled saturation conditions and in the presence of organic contamination by benzene. All results confirm the influence of pollutants in different concentrations on the mechanical behaviour of the soil. They show a strong increase in compressibility and a significant increase in swelling, the soil becomes more cohesive, low friction and less elastic. Furthermore, the results show that external load forces play a major role in modifying the behaviour of clay.

Tight sandstone gas reservoirs of Xujiahe Formation in central Sichuan Basin have generally high water saturation. The characteristics of natural gas migration and accumulation, as well as gas reservoirs with high water saturation formation mechanism, were investigated using test data from natural gas geochemistry analysis and nuclear magnetic resonance (NMR) high pressure filling simulation experiment. The findings reveal that: (1)The Xujiahe Formation established the foundation for oil and gas near-source accumulation by interacting superimposed large areas of source rock and reservoir. As the maturity of source rocks increases, the wetness becomes smaller and the δ13C1 value becomes heavier of natural gas, indicating a near-source accumulation. (2)The gas saturation of Xujiahe Formation gas reservoirs ranges from 50% to 65%, with a pore radius of the reservoir space 0.1–10 μm. The larger the proportion of relatively large pore size, the higher the gas saturation will be. (3)As charging pressure is increased, natural gas accumulates in tight sandstone by progressively aggregating from large pore diameter to small pore diameter space, culminating “three-stage” charging characteristics of rapid increase, moderate increase and basically stable charge. The coupling between low-pressure drive and relatively large pore reservoir is the fundamental reason why the Xujiahe Formation of natural gas can form large-medium gas reservoirs but high water saturation in central Sichuan Basin. The findings will provide theoretical and technical support for the exploration of tight sandstone.

In this paper, the tracking control problem of uncertain Euler–Lagrange systems under control input saturation is studied. To handle system uncertainties, a leakage-type (LT) adaptive law is introduced to update the control gains to approach the disturbance variations without knowing the uncertainty upper bound a priori. In addition, an auxiliary dynamics is designed to deal with the saturation nonlinearity by introducing the auxiliary variables in the controller design. Lyapunov analysis verifies that based on the proposed method, the tracking error will be asymptotically bounded by a neighborhood around the origin. To demonstrate the proposed method, simulations are finally carried out on a two-link robot manipulator. Simulation results show that in the presence of actuator saturation, the proposed method induces less chattering signal in the control input compared to conventional sliding mode controllers.

The problem of Mandelstam-Brillouin stimulated scattering in homogeneous and inhomogeneous plasmas is discussed in an approximation of strong dissipation of sound waves, taking into account the second harmonic nonlinearity and the pump wave depletion. It is shown that the scattered radiation intensity decreases with the distance from the resonance point, followed by its saturation. The level of saturation substantially depends on the characteristic size of the pump wave inhomogeneity and intensity, as well as dissipation of the interacting waves.

Binder jet additive manufacturing (BJ-AM) is a rapidly evolving 3D printing technique where the access to an array of powder materials is expanding. The use of silica sand has grown in popularity within the BJ-AM sector and has been shown to have a high potential of replicating physiochemical properties of natural materials for geoengineering applications. Consistent porosity is critical for 3D-printed samples used in rock testing since homogeneity between samples would provide unlimited capabilities in a laboratory setting. Binder saturation is one of the key user-set parameters that controls the ratio between the dimensional tolerance and porosity. Nonetheless, the binder saturation is an internal calculation by the printer’s software that relies on several assumptions, where the most important physical aspect is droplet spacing. This study establishes relationships between the droplet spacing, dimensional tolerance, binder saturation, and porosity. By holding the droplet volume constant and changing its spacing, better control of saturation was observed. Higher saturation reduced porosity and increased circularity of cylindrical samples, but overall dimensional tolerance of fine features was reduced. This study provides improvements of 3D-printed rock for the representation of porosity and geomechanical properties observed in natural sandstones.

The second production test of natural gas hydrate (referred to as hydrate) reservoir in the Shenhu sea area of the northern South China Sea shows that horizontal wells have greater potential than vertical wells in the depressurization production of hydrate reservoirs, but the length of horizontal section to achieve remarkable development effect has not been determined. To this end, a set of production simulation experiment device was independently designed. After the influences of horizontal well section length on gas and water production behaviors and temperature and pressure change laws during the depressurization development of hydrate reservoirs were studied by means of physical experiment, an equal-scale numerical simulation model was established by numerical simulation method. And based on history matching, the change laws of hydrate saturation and gas saturation were analyzed. And the following conclusions were reached. First, for the hydrate reservoirs where water and hydrate coexist, a great amount of high-pressure movable water is produced in the early stage of depressurization development while the formation pressure drops quickly and hydrates are mostly dissociated. In the later stage of depressurization development, there is no stable heat supply. Therefore, the gas production rate presents a trend of fast rise to the peak in the early stage and then concussive decline. Second, horizontal well can effectively increase the water and gas drainage areas, so the longer the horizontal well section is, the higher the peak gas production rate and cumulative gas production are and the shorter time it takes to reach the peak gas production rate, but the faster the gas production decline is in the case of no heat supply. Third, an obvious low hydrate saturation area is formed near the horizontal well, so a long horizontal section is helpful to enlarge the hydrate dissociation area, but in the later stage of depressurization development, there are still a lot of undissociated hydrates in hydrate reservoirs, so the development mode shall be modified to further promote the dissociation of hydrates. Fourth, due to the heat transfer of cap rocks and the gas/water gravity difference, a secondary gas cap is formed easily in the process of depressurization development, so if the horizontal well is drilled near the upper part of a hydrate reservoir, the overlay of dissociated gas can be alleviated, and consequently the production and development effect of dissociated gas are improved.

Calcite (Cc) has been tested as a potential phosphorus (P) binding agent to be used for non-invasive P removal from lakes. In this approach P binding agent is placed in the water column and subsequently removed together with the sorbed P. Mechanism of orthophosphate (OP) sorption onto Cc and Cc behaviour were investigated under epilimnetic and hypolimnetic temperature, pH and saturation with respect to Cc (25°C, pH = 9.0, saturation index for Cc (SICc) = 1.4, and 10°C, pH = 7.1, SICc = -0.7, respectively) at an initial OP concentration of ∼ 1 mg PO43− L−1 in the range of Cc dosages of 0.01–20.1 g L−1, resulting in OP:Cc mass ratios of 0.06–85 mg:g. Prevailing OP binding processes were adsorption and precipitation, depending on OP:Cc mass ratio (adsorption predominated at low OP:Cc and precipitation at high OP:Cc). Under epilimnetic conditions, approximately five times lower OP:Cc mass ratio was needed to induce precipitation as compared to hypolimnion, indicating at a greater probability of precipitation in epilimnion, while adsorption was more likely to occur in hypolimnion. In epilimnion, co-precipitation of OP was also involved together with adsorption. Calculated maximum adsorption was 35% higher in epilimnion, whereas obtained precipitation rates (measured as unit sorption) were 87% higher, showing promoting effect of epilimnetic conditions on OP removal. Application of Cc into epilimnion will result in a pH drop which can reduce occurrence of cyanobacteria. Application of Cc into hypolimnion will result in its partial dissolution, while most of the applied Cc mass will be removable after the finished treatment.

This paper investigates the semi-global cooperative cluster output regulation problem of heterogeneous multi-agent systems with input saturation, the exosystems for each cluster can be different. To avoid using global information (e.g., the minimal nonzero eigenvalue of the Laplacian matrix) in the control protocol, an adaptive dynamic compensator is proposed to estimate exosystem’s state in fully distributed manner. A dynamic event-triggering mechanism with adaptive parameter is proposed in order to reduce the usage of communication resources. Low-gain feedback technique is utilized to deal with the influence of input saturation, and Lypunov-based stability analysis results are obtained. Moreover, it is formally shown that Zeno behavior can be excluded. The superiority of the proposed methods includes: the agents in each cluster are also heterogeneous, which is essentially different from [1]; the event-triggered control strategy does not depend on any global information; and the influence of saturation nonlinearity can be eliminated with low-gain feedback. Finally, a numerical example is provided to illustrate the effectiveness of the proposed methods.